The purpose of the Population Resources Core (Core) is to provide a central repository for all of the data included in the program project. Included in this Core facility are: a) demographic data on individuals comprising study populations; b) questionnaire-derived data; c) tumor registry data; d) death registry, mortality information; e) description of the biosample collection (serum library, tissue bank); f) laboratory results from field study sites (Senegal, China) and collaborating investigators (e.g. Christopher Wild, Sean O-Broin); g) laboratory data from the General Laboratory Services Core; h) family history information; i) clinical information (patient records, pathology reports, etc.); and j) questionnaire instruments. The information contained in the Population Resources Core is available to all investigators in the program project. The aims of the Core are: 1) Provide computer-based tools that facilitate the storage and retrieval of the data generated in the proposed. Thus, the primary purpose of this Core is to generate and maintain a working, "production" database that provides access to common resources and information. 2) Ensure the accuracy of the database. 3) Organize and maintain the database to maximize accessibility. 4) Provide detailed descriptions of the available populations. 5) Correlate information among the projects. By providing access to the data to all participants, sharing technical capabilities, and ensuring the quality of the data, we believe that this Core facility will continue to facilitate achievement of the aims of the individual projects and encourage exploratory analyses beyond the stated aims of the projects.